overlap_front
if ((prev + 1) >= bb->count && !overlap_front(bb, prev, &bad)) {
if (overlap_front(bb, prev, &bad)) {
((prev + 1) >= bb->count) && !overlap_front(bb, prev, &bad)) {
if ((prev >= 0) && overlap_front(bb, prev, &bad)) {
WARN_ON(!overlap_front(bb, prev, bad));
if (overlap_front(bb, prev, &bad)) {